{
    "action": "tool_call",
    "reasoning": "I need to confirm the column profile (types, nulls, distinct counts) before giving a classification of identifier, categorical, numeric and date columns. I'll pull the column overview metadata in one query.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT column_name, phys_type, semantic_role, rough_kind, null_count, distinct_count, min_value, max_value FROM analytics.column_overview WHERE table_name = 'AI_Usage_and_Impact_on_Students_and_Professionals'",
        "purpose": "Profile all 23 columns by type, role, nulls and cardinality",
        "source": "raw"
    }
}